The research we are undertaking has as its goal the elucidation of the molecular mechanism of carcinogenesis in mammalian cells. The projects to be described in detail below are all based on the supposition that the information for malignancy is contained within each cell and that carcinogenic agents act to trigger the expression of this information. Our approach to testing this hypothesis is to compare the biochemical and biophysical properties of cells transformed to malignancy using chemicals and viruses as carcinogens. If the two agents do trigger the expression of the same information, some of the properties of these two types of malignant cells should be identical. It is our hope that we can determine the common events in all types of neoplastic transformations and not only obtain a better understanding of growth control in mammalian cells, but also design possible ways of interrupting the onset of malignancy.